1. Field
Apparatuses consistent with exemplary embodiments relate to a zoom lens system and a photographing apparatus using the same, and more particularly, to a zoom lens system applicable to a camera such as a surveillance camera, a video camera, a digital still camera, or a broadcasting camera, and a photographing apparatus, not being limited thereto, using the zoom lens system.
2. Description of the Related Art
In the related art, a positive-negative-positive-positive four group zoom lens system is known as an example of a zoom lens system having high image quality and high magnification, and suitable to a surveillance camera, a video camera, a digital still camera, or a broadcasting camera. The positive-negative-positive-positive four group zoom lens system includes a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and fourth lens group having positive refractive power, sequentially from an object side. During variable magnification (also known as “zooming”) from a wide-angle position to a telephoto position, the first and third lens groups are fixed in an optical axis direction, the second lens group move from an object side to an image side, and the fourth lens group moves in the optical axis direction so as to compensate for an image plane change generated as the second lens group move from an object side to an image side while performing a focusing function, i.e., focusing.
Recently, it has been required to obtain an optical performance corresponding to a high pixel photographing apparatus and maintain a satisfactory performance even during short distance focusing. JP 2010-139724 (hereinafter, referred to as “a patent reference 1”) discloses a method of distributing positive refractive power by disposing three negative lenses and three positive lenses in a first lens group, as a method of obtaining an optical performance of the telephoto position. Also, JP 2010-102096 (hereinafter, referred to as “a patent reference 2”) discloses a positive-negative-positive-positive four group zoom lens system, wherein a second lens group includes at least two negative lenses.
However, the zoom lens systems disclosed in the patent references 1 and 2 do not show optical performances corresponding to a high pixel photographing apparatus while having a small size and variable magnification. For example, in the patent reference 1, only 20 times variable magnification is obtained. Also in the patent reference 1, a high performance is promoted by including a negative lens, a meniscus negative lens, and a cemented lens of a negative lens and a positive lens in a second lens group sequentially from an object side to an image side to distribute negative refractive power, and by compensating for comma aberration generated according to a viewing angle change at the wide-angle position. However, an optical performance is not satisfactory in the patent reference 1 since chromatic aberration is not sufficiently compensated for due to unsuitable location of a positive lens. Also, in the patent reference 2, a zoom lens system having 30 times variable magnification cannot be obtained.